What lights does a vessel restricted in her ability to manoeuvre show?
Three all-round lights in a vertical line: red, white, red. By day: ball, diamond, ball (Rule 27(b)).
Restricted in her ability to manoeuvre (RAM) means the nature of her work stops her keeping out of the way: dredging, surveying, laying cables or buoys, replenishing at sea, launching aircraft, mine clearance, or a tow she can't turn away from.
- Making way: she adds masthead light, sidelights and sternlight. At anchor: anchor lights or ball.
- Dredging or underwater work with an obstruction: two reds (or two balls) on the side to avoid, two greens (or two diamonds) on the side you can pass.
- Small dive boats may show a rigid code flag A instead.
- In fog: one prolonged and two short blasts at least every 2 minutes.
- Vessels under 12 m (except diving operations) needn't show these signals.
Source: COLREGS Rule 3(g), Rule 27(b) to (e) and Rule 35(c).
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